The Argus-II Retinal Prosthesis Implantation; From the Global to Local Successful Experience.

Over the past few years, visual prostheses (namely, Argus II retinal implant) and gene therapy have obtained FDA approval in treating blindness resulting from retinitis pigmentosa. Compared to gene therapy; Argus II is less costly with a demonstrated favorable outcome, though the vision is yet artificial. To obtain better results, expectation counseling and preoperative retinal assessment are critical. The global experience with Argus II has enrolled no more than 300 cases so far. The first Argus II retinal prosthesis in Iran was successfully implanted in Shiraz (October 2017). To date, Argus II artificial retina is implanted in four patients in Iran. Beside successful surgery and post-operative care, rehabilitation efforts with validated outcome measures including visual rehabilitation together with neurovisual, visuo-constructive and cognitive rehabilitation/empowerment approaches are expected to boost the functional outcome. A multidisciplinary approach within a cross-functional team would optimize strategies toward better patient outcomes. As such, establishing a collaborative network will foster organized research efforts to better define outcome assessment and rehabilitation strategies. This technology report paper has been an attempt to provide an overview of Argus-II retinal implant global experience as well as the clinical outcome of the so far cases in Iran. Insights from this report were communicated during the first "Brain Engineering and Computational Neuroscience Conference," 31 January-2 February 2018 in Tehran.

Intravitreal Injection of Anti-vascular Endothelial Growth Factor Agents for Ocular Vascular Diseases: Clinical Practice Guideline.

PURPOSE: To provide the clinical recommendations for the administration of intravitreal anti-vascular endothelial growth factor (VEGF) drugs especially bavacizumab for ocular vascular diseases including diabetic macular edema, neovascular age-related macular degeneration, myopic choroidal neovascularization, retinal vein occlusion and central serous chorioretinopathy. METHODS: Twenty clinical questions were developed by the guideline technical committee. Relevant websites and databases were searched to find out the pertinent clinical practice guidelines to answer the questions. The technical committee provided possible answers (scenarios) according to the available evidences for each question. All scenarios along with their levels of evidence and the supported articles were sent to the experts for external review. If the experts did not agree on any of the scenarios for one particular clinical question, the technical committee reviewed all scenarios and their pertinent evidences and made the necessary decision. After that, the experts were asked to score them again. All confirmed scenarios were gathered as the final recommendations. RESULTS: All the experts agreed on at least one of the scenarios. The technical committee extracted the agreed scenario for each clinical question as the final recommendation. Finally, 56 recommendations were developed for the procedure of intravitreal anti-VEGF injection and their applications in the management of ocular vascular diseases. CONCLUSION: The implementation of this guideline can standardize the management of the common ocular vascular diseases by intravitreal injection of anti-VEGF agents. It can lead to better policy-making and evidence-based clinical decision by ophthalmologists and optimal evidence based eye care for patients.

Intravitreal infliximab for the treatment of sight-threatening chronic noninfectious uveitis.

PURPOSE: Tumor necrosis factor-alpha is known to play an important role in various immune-mediated ocular diseases. Infliximab, a chimeric monoclonal antibody against tumor necrosis factor-alpha, has been used for the treatment of various chronic systemic and ocular inflammatory diseases. The purpose of this study was to evaluate the effect of intravitreal injection of infliximab on the visual acuity and central macular thickness in patients with chronic noninfectious uveitis. METHODS: Ten eyes of 7 patients with chronic persistent noninfectious uveitis who were nonresponsive to conventional previous medications during the previous 3 months were included in this study. The patients received intravitreal injection of 1.5 mg/0.15 mL infliximab. Mean best-corrected visual acuity and mean central macular thickness 1 day before and 4 weeks after the injection were evaluated and compared. RESULTS: Mean logarithm of the minimum angle of resolution before and after injection was 1.37 ± 0.43 and 0.67 ± 0.56, respectively, with statistically significant improvement after injection (P = 0.005). The mean central macular thickness before and after injection was 673.20 ± 338.39 µm and 456.40 ± 317.46 µm, respectively, with a significant decrease in the central macular thickness after the injection (P = 0.005). CONCLUSION: Intravitreal injection of infliximab may improve the visual acuity and decrease the central macular thickness in patients with chronic noninfectious uveitis and significant visual loss and central macular edema.

Herpetic epithelial keratitis after intravitreal injection of bevacizumab (avastin).

PURPOSE: To report a case of herpetic epithelial keratitis that developed after intravitreal bevacizumab (Avastin) injection. METHODS: A 63-year-old man with diabetes with proliferative diabetic retinopathy and macular edema received intravitreal injection of bevacizumab (Avastin) in his right eye. RESULTS: Three days after the injection, the patient presented with foreign body sensation, redness, tearing, photophobia, and decreased visual acuity in the right eye. The cornea showed an arborizing dendritic epithelial lesion with terminal bulb typical of herpes simplex virus (HSV) epithelial keratitis. HSV-DNA was detected in corneal scrapings using polymerase chain reaction. A diagnosis for herpes simplex epithelial keratitis was made. Topical acyclovir ointment therapy was initiated with good resolution of HSV signs and symptoms. CONCLUSIONS: Herpes simplex epithelial keratitis can be a possible complication of intravitreal bevacizumab (Avastin) injection. To our knowledge, this case is the first report of herpetic epithelial keratitis after intravitreal bevacizumab (Avastin) injection.

Effect of intravitreal triamcinolone acetonide in the treatment of experimental Staphylococcus epidermidis endophthalmitis.

PURPOSE: To investigate the effect of intravitreal injection of triamcinolone acetonide (TA) in the treatment of experimental Staphylococcus epidermidis endophthalmitis. MATERIALS AND METHODS: Experimental endophthalmitis induced in one eye of 38 rabbits by intravitreal injection of Staphylococcus epidermidis. The infected rabbits were randomly divided into three groups. The rabbits in group 1 (n = 15) received intravitreal injection of 1 mg vancomycin hydrochloride. Group 2 eyes (n = 15) received intravitreal TA (4 mg) plus vancomycin hydrochloride (1 mg). Group 3 eyes (8 eyes) received normal saline. Clinical examination in each group was performed two, seven, and 15 days after inoculation of the bacteria. The eyes were enucleated for histopathologic evaluation on the 15th day. Clinical and histological scoring systems were used to evaluate clinical and histological severity of the intraocular infection. RESULTS: The mean clinical scores of three study groups at the 7th day were 5.8 +/- 2.3, 3.3 +/- 1.5, and 9.5 +/- 2.1, respectively. The mean of this value at 15th day were 6.2 +/- 2.6, 3.9 +/- 2.1, and 10 +/- 2.2, respectively. At the 7th and 15th day, the mean clinical score of group 2 was significantly lower when compared with the other two groups. Mean histopathologic scores of group 1, group 2, and group 3 were 11 +/- 2.7, 7.9 +/- 2.9, and 14.0 +/- 3.1, respectively. Histopathologic studies revealed less tissue destruction for eyes treated with TA. There was a significant positive correlation between the severity of clinical signs and pathologic damage in all three experiment groups; however, it was weakest in the IVTA treated group. CONCLUSION: A standard clinical dose of intravitreal TA attenuates the clinical signs and tissue destruction in a rabbit model of Staphylococcus epidermidis endophthalmitis.

The relation between serum homocysteine level and eye involvement in Behçet's disease.

BACKGROUND: Behçet's disease is a chronic, multisystemic disease of unknown etiology in which eye involvement is the most common cause of morbidity. In this study, we investigated the possible relation between serum homocysteine level and ocular involvement in patients with Behçet's disease. METHODS: One hundred and fifty patients who fulfilled the criteria of the International Study Group for Behçet's disease (96 females and 54 males) were enrolled. All the patients were evaluated carefully by an experienced ophthalmologist for the diagnosis of ocular involvement. Serum homocysteine, vitamin B12, and folate levels were determined. The patients were categorized according to the presence or absence of uveitis. The data were statistically analyzed by using Student's t-test and P values less than 0.05 were considered statistically significant. RESULTS: Fifty- nine patients (39.3%) had eye involvement, which included anterior uveitis, vitritis, macular damage, optic atrophy, panuveitis, posterior uveitis, retinal vasculitis, and retinal hemorrhage. Serum levels of folate and vitamin B12 were comparable in patients with Behçet's disease. There was no significant correlation between serum homocysteine level in patients with and without eye involvement. CONCLUSION: Our findings suggest that homocysteine level does not have significant effect on eye involvement in patients with Behçet's disease.

Triamcinolone-assisted neodymium:YAG laser vitreolysis.

Triamcinolone acetonide was injected into the vitreous cavity to treat a case of cystoid macular edema. After the injection, slit-lamp examination was performed and the vitreous strands adhered to the remaining edge of the posterior capsule were clearly visualized. The strands were dissected with neodymium:YAG (Nd:YAG) laser shots. A technique that can be used to facilitate diagnosis and Nd:YAG laser dissection of vitreous strands in cases with complications of adhesion of vitreous strands into anterior segment structures is described.

Bevacizumab inhibits corneal neovascularization in an alkali burn induced model of corneal angiogenesis.

BACKGROUND: New and uncontrolled blood vessel development in the cornea is a pivotal process in the pathogenesis of several corneal diseases. These corneal diseases may finally cause blindness and managing them therapeutically is problematic. The data supporting a causal role for vascular endothelial growth factor in corneal neovascularization are extensive. This study aimed to evaluate the effect of subconjunctival bevacizumab (Avastin) on experimental corneal neovascularization in rabbits. METHODS: Chemical cauterization of the cornea was performed by touching central cornea with a 5-mm-diameter NaOH-soaked cotton applicator for 10 s in 20 eyes of 20 White New Zealand rabbits. The rabbits were then divided randomly into two equal groups. Bevacizumab (2.5 mg) was administered to 10 eyes (group 1) by a subconjunctival injection immediately after chemical cauterization of corneal surface. As a control, 10 eyes (group 2) received an injection of distilled water. Rabbits were examined daily for detection of the first signs of neovascularization. Three weeks later, the extent of corneal neovascularization was evaluated by direct examination and photograph analyses. Total corneal neovascularization area, degree of circumference involved and longest neovascular pedicle length were assessed. RESULTS: Bevacizumab significantly decreased the total neovascularization area (P < 0.009), the circumference involved (P < 0.011) and the longest neovascular pedicle length (P < 0.023). CONCLUSION: Local injection of bevacizumab has a significant effect on inhibition of alkali burn-induced corneal neovascularization. This shows the potential value of bevacizumab in the treatment of corneal neovascularization.

Focus on triamcinolone acetonide as an adjunct to glaucoma filtration surgery.

Glaucoma is one of the most common causes of irreversible blindness worldwide. Despite continued advances in medical and laser therapy, incisional surgery still appears to be an important and for many cases the only option by which intraocular pressure is controlled. Unlike many other types of surgery in which complete healing of tissue would be a desirable outcome, glaucoma surgery seeks to achieve incomplete healing to allow aqueous humor to escape the eye. Pharmacologic modulation of wound healing is a hot topic in glaucoma filtration surgery. Although routine antifibrotic medications are associated with good results in modulating wound healing in glaucoma surgery, they carry with them the possibility for significant morbidity due to the adverse effects of treatment. Challenge continues to be to find a safe and effective agent for this purpose. Because of beneficial effects of triamcinolone acetonide in some conditions which are associated with secondary glaucoma and also potential effects of this agent in modulating wound healing process, we propose it as a useful adjunct to glaucoma filtration surgery. This approach may allow modulation of wound healing with less of the toxicity associated with commonly used antifibrotics (5-FU and mitomycin C).

Potential role of uric acid in the molecular pathogenesis of age-related macular degeneration.

Age-related macular degeneration (ARMD) is the foremost cause of blindness among the elderly population in industrialised countries. Currently, there is no effective treatment for the majority of patients. To develop new and effective modes of therapy, understanding of the molecular basis of the disease is mandatory. Many age-related pathologies have been attributed to cumulative oxidative damage caused by reactive oxygen intermediates. There is growing evidence that uric acid has antioxidant properties and it is a naturally occurring antioxidant. Based on antioxidant role in pathogenesis of ARMD and antioxidant properties of uric acid we conclude that altered uric acid metabolism could play a role in ARMD damage and pathogenesis. Future research needs to evaluate uric acid metabolism in ARMD patients.

Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment: six-month follow-up results of a single operation--report no. 1.

PURPOSE: To compare the anatomic and visual results and complications of conventional scleral buckling versus primary vitrectomy for management of pseudophakic and aphakic retinal detachment. DESIGN: Prospective, randomized, multicenter clinical trial. PARTICIPANTS: Two hundred twenty-five eyes of 225 patients with pseudophakic or aphakic retinal detachment. INTERVENTION: Eligible eyes were assigned randomly either to conventional scleral buckling or primary vitrectomy without any buckle. MAIN OUTCOME MEASURES: Visual results, retinal reattachment rate, proliferative vitreoretinopathy, macular pucker, cystoid macular edema, choroidal detachment, intraocular pressure, extraocular muscle dysfunction, and anisometropia. RESULTS: There were no statistically significant differences between the 2 treatment groups regarding the single-operation retinal reattachment rate at the 1-, 2-, 4-, and 6-month follow-up examinations. Patients in the buckle group had 28% greater likelihood of anatomic success compared with those in the vitrectomy group (odds ratio, 1.28; 95% confidence interval, 0.73-2.24), indicating no statistically significant difference. Proliferative vitreoretinopathy was the main cause of anatomic failure in both groups and occurred independent of the surgical technique used. Best-corrected visual acuity at the 1-, 2-, 4-, and 6-month postoperative follow-up examinations showed no statistically significant difference between the 2 groups. Six months after surgery, 12.8% of eyes in the buckle group and 11.3% of eyes in the vitrectomy group achieved visual acuity of 20/40 or better. The difference between the 2 groups was not statistically significant. Corresponding figures were 66.3% and 64.5% for visual acuity of 20/200 or better in the buckle and vitrectomy groups, respectively, again with no statistically significant difference. There were no statistically significant differences in rates of complications. CONCLUSIONS: Scleral buckling and primary vitrectomy without an encircling band have comparable results in pseudophakic and aphakic retinal detachment. The choice of surgical technique depends on various factors, including patient compliance, cost of surgery, experience and capability of surgeons, and availability of appropriate instrumentation.